The present invention relates to an ink-jet type image-forming apparatus (hereinafter referred to as an xe2x80x9cink-jet imaging apparatusxe2x80x9d) which prints images by ejecting ink onto a recording medium.
Ink-jet imaging apparatuses for printing by ejecting ink onto a recording medium are known as a kind of output apparatus of computers and work stations. The ink-jet imaging apparatuses are generally provided with a printing head which has plural ink ejection outlets, a carriage which carries the printing head and is moved in reciprocation in a prescribed main scanning direction, and a delivery device which delivers a recording paper sheet in the direction perpendicular to the main scanning direction (the recording medium delivery direction, hereinafter referred to as a xe2x80x9csub-scanning directionxe2x80x9d).
In formation of an image on a recording paper sheet, the delivery of the recording sheet is temporarily stopped, and an ink is ejected through an ink ejection outlet with the reciprocating movement of the carriage in the main scanning direction in accordance with image signals to form one printing band portion of an image on the area of the recording sheet placed on an image formation zone confronting the ink ejection outlet. Then the recording paper sheet is delivered by a distance of one printing band breadth and stopped, and again an ink is ejected through an ink ejection outlet with the reciprocating movement of the carriage in the main scanning direction in accordance with image signals to form another printing band portion of an image on the newly delivered area of the recording sheet on the image formation zone. By repeating the operation, an entire image is formed on the recording paper sheet.
The printing head and the carriage have respectively a circuit face (circuit pattern) to transmit the image signals. The each of the circuit faces has plural electric connection points for electric connection. The pairing of the connection points of the one circuit face with those of the other circuit face is predetermined. Interconnection of the predetermined pairs of the electric connection points enables precise transmission of image signals from the carriage to the printing head. Thus, in the ink-jet imaging apparatus, on mounting the printing head onto the carriage, the electric connection points of the circuit face formed on the printing head is precisely connected with the electric connection points of the circuit face formed on the carriage.
In order to achieve precise electric connection between the electric connection points of the printing head and those of the carriage, the printing head and the carriage are made with high-precision. Thereby, by mounting the printing head onto the carriage, the electric connection points of the both parts will be electrically connected precisely. In recent years, with downsizing of the imaging apparatus, the carriage and the printing head are coming to be miniaturized. For the miniaturization, the densities of the electric connection point distribution on the circuit faces are made higher. Also, for improvement of the image resolution, the aforementioned densities of the electric connection points on the circuit faces are being increased.
With such a higher density of the electric connection points, the contact points of the printing head and the carriage could be unprecisely interconnected even if the printing head and the carriage are produced with high precision. The unprecise interconnection may cause error in image signal transmission to result in incorrect ejection of the ink from the printing head, which lowers the image quality.
Under the aforementioned circumstances, the present invention intends to provide an ink-jet imaging apparatus in which the electric connection points of a printing head and those of a carriage are precisely interconnected even at a high density of the connection points.
For achieving the above object, the ink-jet imaging apparatus of the present invention is provided with a printing head having a first circuit face having plural first electric connection points, and a carriage having a second circuit face having plural second electric connection points to be connected respectively to the first electric connection points, and forms an image by ejecting an ink from the printing head with reciprocating movement of the carriage in a main scanning direction in accordance with image signals transmitted through the first electric connection points and the second electric connection points, wherein
(1) one of the first circuit face and the second circuit face moves to follow the other circuit face;
(2) the first circuit face may follow the second circuit face by movement in a direction crossing the second circuit face;
(3) the second circuit face may follow the first circuit face by movement in a direction crossing the first circuit face;
(4) the first circuit face may follow the second circuit face by movement in a direction nearly parallel to the second circuit face;
(5) the second circuit face may follow the first circuit face by movement in a direction nearly parallel to the first circuit face.
The ink-jet imaging apparatus may be provided also with
(6) a contact base which has the second circuit face fixed thereon and follows the first circuit face by movement in the crossing direction, and
(7) a pushing member which is held at least between the second circuit face and the contact base, or between the first circuit face and the printing head;
(8) the contact base may follow the first circuit face by movement in a direction nearly parallel to the first circuit face;
(9) the contact base may be replaced by another contact base which has the first circuit face fixed thereon and follows the second circuit face by movement in the crossing direction;
(10) the contact base may follow the second circuit face by movement in the direction nearly parallel to the second circuit face;
(11) the contact base may have a protrusion formed near the gravity center of the contact base and touching the carriage;
(12) the contact base may follow the first circuit face or the second circuit face by swing movement around the touching point of the protrusion touching the carriage as the center;
(13) the carriage may have a protrusion to touch the contact base at or near the gravity center of the contact base;
(14) the contact base may follow the first circuit face or the second circuit face by swing movement around the touching point of the protrusion touching the contact base as the center; and
(15) the first circuit face or the second circuit face confronting the pushing member may be flexible.